Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Copolyamides based on poly(m-phenylene isophthalamide) and poly-(p-phenylene terephthalamide), to which 1,6-diaminohexane units were regularly inserted every 3 or 5 phenylene monomer units, were synthesized. The copolymers were obtained by condensation of individually prepared diamino- and dicarboxylic-building blocks…
Porous Y2O3 ceramic was found to show huge thermopower values up to −50 mV/K at 900–1000 K in vacuum, but not in air. Such huge thermopowers may be generated by the electron gas emitted from the internal surfaces of the pores and are associated with some unknown effects. The nondimensional thermoelectric figure of mer…
Collagen was purified from bovine Achilles tendon and crosslinked with dimethyl suberimidate (DMS) and glutaraldehyde (GTA). Under optimal conditions, the shrinkage temperature (Ts) was raised to 74 degrees C for collagen crosslinked with DMS and to 80 degrees C for those crosslinked with GTA. Crosslinking density mea…
This paper presents the results of dielectric dispersion in Ba 2 NaNb 5(1- x ) Ta 5 x O 15 (BNNT) single crystals over the frequency range 1 kHz to 4 GHz. The fundamental dielectric dispersion occurs above 10 7 Hz and is caused by a soft relaxational mode. This mode gives the main contribution to the high static permi…
Medical-grade silicone elastomers were subjected to accelerated aging in saline to verify the hydrolytic stability of the elastomer. Tensile strength, elongation at break, and the elastomer stress measured at 100% or 200% elongation did not change significantly for peroxide-cured sheeting aged in 37 degrees C or 100 d…
We present a flexible and computationally efficient scheme for calculating electronic eigenstates of semiconductor nanocrystals using Wannier functions. With this method, we compute the band gap of CdS nanocrystals and compare our calculations with experiment. This approach also enables us to study the dependence of t…
We study morphology of chemically reacting binary mixtures quenched into a thermodynamically unstable region. One of the characteristic features of the system which has not been studied so far is that one can change the average volume fraction during the phase separation process. Computer simulations are carried out i…
A multiple–order–parameter theory of ordering on a binary face–centred–cubic (FCC) crystal lattice is developed, and adapted to provide a continuum formulation that incorporates the underlying symmetries of the FCC crystal in both the bulk and gradient–energy terms of the free energy. The theory is used to compute the…
The electron field-emission process for nitrogenated amorphous carbon (a-C:H:N) thin films deposited using a magnetically confined hydrocarbon plasma is examined. The morphology of the films obtained using an atomic force microscope is compared to the field-emission properties. Beyond a chemical composition of 14 at.…
4,4′-Diaminodiphenylacetylene (p-intA) was reacted with 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and pyromellitic dianhydride (PMDA) in N-methyl-2-pyrrolidone (NMP) to give poly(amic acid) solution of moderate to high viscosity. Thermal imidization…
We have directly measured the absolute efficiency of the 9.8-eV $M$-band luminescence from the decay of ${\mathrm{Ar}}_{2}^{\mathrm{*}}$ excimers in solid Ar bombarded by 1.5-MeV ${\mathrm{He}}^{+}$ and 10--50-keV ${\mathrm{H}}^{+}$ ions. About 54% of the electronic energy deposited by the projectiles is converted to…
We investigated the tissue distribution of vancomycin (VCM) incorporated in fibrin glue (FG) in a rat model. One VCM-loaded FG Dacron graft (VCM-FG, VCM 0.6 mg/ graft) was implanted in the subcutaneous tissue of the anterior abdominal wall of each rat. VCM was injected intravenously at an equal dose (0.6 mg/rat) after…
The precise value of linewidths obtained after correcting for the slitwidth effect for five Raman bands associated with the core of a liquid crystalline compound, terepthal-bis-decyl aniline (TBDA), have been studied in the temperature range of 12 - 472 K. The variation of the linewidth with temperature confirms two a…
It is not clearly understood how and why the Raman intensity increases drastically with an increasing chain length of polyenes. We therefore investigated the vibrational intensities of the C=C stretching vibrational modes of four polyene systems of X–(HC=CH)n–Y, where X/Y=H/H, H/NH2, H/NO2, and NH2/NO2. The investigat…
An accurate width is determined for the valence band of diamond by imaging photoelectron momentum distributions for a variety of initial- and final-state energies. The experimental result of 23.0\ifmmode\pm\else\textpm\fi{}0.2 ${\mathrm{eV}}^{2}$ agrees well with first-principles quasiparticle calculations (23.0 and 2…
We report on the lattice location of Er in Si using the emission channeling technique. The angular distribution of conversion electrons emitted by the decay chain ${}^{167}\mathrm{Tm}$ $({t}_{1/2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}9.25\phantom{\rule{0ex}{0ex}}\mathrm{d}){\ensuremath{\rightarrow}}^{167m…
We use ab initio and parametrized calculations to investigate the morphology and structural stability at the growing edge of multiwall carbon nanotubes. We find that these open-ended structures are stabilized against dome closure by strong covalent bonds connecting the exposed edges of adjacent walls. Growth at the op…
We report on the first measurements of thermal conductivity in the superconducting state of $(\mathrm{TMTSF}{)}_{2}{\mathrm{ClO}}_{4}$. The electronic contribution to heat transport is found to decrease rapidly below ${T}_{c}$, indicating the absence of low-energy electronic excitations. We argue that this result prov…
The effect of antioxidant on the reaction mechanism of chemical crosslinking of polyethylene (PE) with dicumyl peroxide (DCP) at high temperatures was investigated by electron spin resonance (ESR). The antioxidant reacts with the alkyl radicals in PE formed by the thermal decomposition of DCP above 120°C, and disturbs…
Ausgehend von einem Diphosphazen als molekularem Precursor konnte erstmals phasenreines HP 4 N 7 synthetisiert werden. Die Strukturaufklärung gelang durch Pulver‐Röntgenbeugungsanalyse unter Verwendung von Synchrotronstrahlung. Rechts ist ein Ausschnitt aus der Kristallstruktur gezeigt. magnified image